Apparatus for sanding



Nov. 4, 1941. F. w. ADAMS APPARATUS FOR SANDING 2 Sheets-Sheet 1 FiledAug. 25, 1958 F. W. ADAMS APPARATUS FOR SANDING Nov. 4, 1941.

Filed Aug. 25, 1938 v 2 Sheets-Sheet 2 FLOYD w. ADAMS Patented Nov. 4,1941 UNITED STATES PATENT- OFFICE APPARATUS FOR SANDING Floyd W. Adams,Metuchen, N. J., assignor to The Celotex Corporation, Chicago, 111., acorporation of Delaware Application August 25, 1938, Serial No. 226,6944 Claims. (Cl. 51-190),

ing or abrading operation is accomplished by the action of relativelyinflexible abrading members, which, although the abrading member itselfmay not be inflexible, the effect thereof is relatively inflexible dueto the fact that where the abrasion occurs the abrasive is backed bysubstantially inflexible rolls or the like. 7

The invention hereof differs: from the conventional sanding machine inthat the machine is so constructed that the abrasive action upon thesurface being sanded is what might be termed a flexible abrasive actionsince the abrasive is mounted resiliently order that the abrasive effectmay be self-adjusting depending upon the surface being sanded.

The object of the invention is the provision of a sanding machine whichis especially adapted to sanding a surface rather than to sand to asurface, or otherwise expressed, the sanding machine comprising theinvention is adapted to sand an approximately equal amount from allportions of the surface rather than to sand unequal amounts from variousportions thereof while a surface being sanded with. the ordinary sandingmachine, depending upon the irregularity of the original surface, at thehigh spots receives a relatively heavy sanding with but little or nosanding of the spots in the surfaces which are relatively low.

Other and further objects of the invention are the provision of asanding machine especially adapted for the accomplishment of the primaryobject of the invention as aforesaid, which machine shall be simple inconstruction and economical in operation and which incorporates thereinnew and novel features in the construction thereof. These other featureswill become fully apparent upon reading the following description takenin connection with the accompanying drawings.

A particular feature of the invention is in connection with theconstruction of the sanding roll which is so constructed that theabrasive material acting upon the surface to be sanded is so mountedthat the mounting thereof gives or yields according to the elevation ofa particular portion of the surface being sanded, so that there is notendency for every part of the "surface being sanded to be sanded to auniform plane but instead there is removed from the entire surfacebeingsanded a substantially uniform amount of material.

The inventions hereof are described in the following specification inconnection with the construction as illustrated in the accompanyingdrawings, wherein:

Figure 1 is a side elevation of the complete 7 I sanding machine withunnecessary detailed conillustrated'in Figure 4.

In the embodiment of the invention as illustrated, the sanding machinecomprises a novel sander roll construction having top and bottom sandersA. and B. The top and bottom surface sanders are similarly formed andcomprise a supporting frame base Ill. The supporting frames of the topand bottom sanders A and B are suitably interconnected by conveyor tableframe constructions H and t2. Referring to Figures 1 and 2, thesupporting frame ID has mounted thereon an inverted U-shaped yoke l3 forsupporting respectively an upper sander roll unit C and a lower sanderroll unit D,

The upper sander roll unit C has been illustrated asadjustable while thelower roll D has. been illustrated in a fixed position. It is to beunderstood, however, as within the scope of the invention, that the.sander roll units may be either'fixed or adjustable; As illustrated, inFigures I and 2, the sander roll unit C is suitably supported from theinverted, yoke l3. by cross members [4 and I5 to which are suitablyconnected bearing guides I 6. is suitably journaled in a bearing l8which is adjustably mounted on the guides 16.

The sander roll unit C is adjusted vertically through an adjusting meanshaving a ball and socket joint connection [9 to. the bearing I8.Adjustment of the sander roll unit C is accomplished through anadjusting screw 20 suitably threaded through cross members M of yoke l3and having on itslower end the ball. portion'o-f ball and socket joint19 and is actuated through an adjusting wheeIZl. It is thereforeapparent A. shaft or arbor l1 chine.

that by actuating the adjusting wheels 2| of the sander roll unit C thatthe sander roll unit may be vertically raised and lowered to adjust formaterial which is to be surface sanded having various thicknesses.

As the material which is being sanded is fed through the sanding machineby the conveyor tables I] and I2, 'itis obvious that when the materialcomes to the lower sander roll unit that means for applying pressure tothe material'as it is being sanded on its lower surface is necessary. Asimple pressure attachment for the lower sander roll unit will now bedescribed.

Pressure rolls 22 for contacting themateria-l as it enters and leavesthe bottom surface sander. unit B are suitably supported on shafts 23which are suitably pivoted by pressure roll arms 24 mounted on theinverted U' shaped yoke I3.

arbor I! of the upper sander roll unit C. Intermediate the right handyoke l3 and the sander roll unit C is mounted a drive pulley 46 fromwhich the lower sander roll unit B is driven.

The conveyor belt 3| of the conveyor units H and I2 are actuated fromthe jack shaft 36 by a belt 41 running over pulleys 42 and 38 which inturn drive the conveyor drive pulley 32 by the belt 39 running over thepulley 31.

The driving means for actuating simultaneously the upper and lowersander roll units C and D comprise a continuous belt 48 passing over thepulleys 46 and pulley 4| to provide for an increase surface contact ofthe belt 48 over its At the inner ends the arms 24 are pivotally at-.

tached at 25. A pressure roll spring 26 is mount'-' ed at theconnecti0n25'and secured at its upper end to vanladjustingscrew. 21..Thepressure rolls are 'suitablyadjusted on each side of the sandingmachine by an adjusting .hand wheel 28.

The conveyor tables II .and' |2 which comprise the mechanism for feeding.the materialthrough the sanding machine are illustrated in Figures 1and 3; and, in this specific embodiment of the invention the materialwhich is .tobe sanded is in slabs having a relatively fiat surface oflarge area. The conveyor tables Hand I2 which are suitably .supportedbyv the framework of the top and bottom surface sanders A and B alsoserve as support for conveyor shafts '29 of the conveyors entering andleavingjthe sanding ma- As each conveyor is'similan'like referencecharacters will denotesimil'arparts. i Suitably secured to the conveyorshafts '29 are conveyor rolls or pulleys 30 over which'run conveyorbelts 3|. A conveyor drive' pulley' 32 mounted on the conveyor table lladj'acent the bottom surface sander'B serves to" operate both conveyors.The conveyors are voperatively connected to operate in the samedirection-through a belt or similar drive running over connecting drivepulleys 33. 4 v

The driving mechanism for actuating the conveyors for the top and bottomsurface sanders A and B and'also' the upper and lower sander roll unitsvC and D is of conventional construe tion. Referring to Figurel, thevarious drives will be described. Cross members 34' mounted on the frameI0 of the top surface sander A support bearings 35 in which arejournaled drive shafts 36. As the supporting structure for the driveshaft '36 on both units A' and B are the same, like reference characterswill indicate similar parts. On the bottom of surface sander B a pulley31 is secured to the shaft 36. A larger pulley 38 is for decreasing thespeed of the feed of the conveyors as they are operated from the samesource of power as the sander roll units which are operated at a muchhigher rate of speed. A belt 39 operatively connects the pulley 31 withthe conveyor drive pulley32,

Pulleys 4| and 42 are suitably mounted on the shaft 36: of thetopsurface sander A. An idler pulley 43 for the drive of the sand-erroll units C and D is supported on "a'shaft 44 suitably mounted on theconveyor table frame connecting the top and bottom surface sanders A andB and is adjacent to thesander unit D. Referring to Figures 1 and,2, amain drive pulley 45 is secured to the outer end of the shaft orrespective pulleys. The belt is returned over the idler 43 which alsoserves as an idler and belt tightener. It 'is, therefore, apparent fromthe foregoing description of the drive for the sander roll units 0 and Dand from the description of the conveyor drives that as the sander rollunits C and D are driven, the conveyor belts are driven but at a reducedspeed. To aid in supportin the material as it is fed by means of theconveyor belts 3| of the conveyor tables II and I2. suitable conveyorsupporting rolls 49 are mounted on the conveyor table frames and |2.

In order to accomplish the object of the invention which is to provide asanding machine especially adapted to sanding a surface and particularlya relatively flat surface of large area, a novel sander roll unit is aparticular feature of the invention. In order to mount the abrasivematerial of the sander roll unit, a new and novel construction will be"described with theyaid of Figures 3, 4 and 5. As thesander roll units CandD are similar, like reference characters will indicate similarconstruction. Each'sander roll unit C and D can be considered asa drumwhich has a deformed surface and which may be considered as fl'exible orresilient so that -as the sander roll unitsare operated, there isremovedfrom the entire surface by sanding asubstantially uniform amount ofmaterial. The abrasive action of the sanding roll units as they act uponthe surface being sanded is what might be termed a flexible abrasiveactionfsince the abrasive is mounted either flexibly or resiliently inorder that the abrasive effect, depending upon the surface being sanded,may be self adjusting. The term resiliently as used within the scope ofthe claims covers equivalent construction such as springs or rubbermounting; and, in the particular embodiment illustratedit .refers to aspring covered member upon which an abrasive material is mounted. Theterm flexibly as used within the scope of the claims is a broader termthan the specific term resiliently, and it is used generically toinclude constructions falling under the term resiliently as well as anyloosely mounted abrasive material forming a sander roll unit asillustrated.

In the particular embodiment illustrated in Figures 4 and 5, the sanderroll units C and D are suitably formed in the shape of adrum which has ahub50 secured tothe shaft IT. The drum is made up of rings 52 suitablyconnectedwith the hub 50 by spokes 5|. Bars 53 suitably spaced radiallyabout the rings 52 serve to form the outer surface of the drum to whichthe abrasive material is attached.

As best illustrated in Figures 3, 4, and 5, a spring steel supportingmember 54 forms a resilient mounting for the abrasive which is appliedthereto in strips or in any suitable manner.

The abrasive surface formed by the abrasive strip 54 is helically coiledabout the outer surface of the drum. It is coiled in such a manner thatas the strip advances for the pitch of the helix, there is formed anelliptical surface for each pitch advanced. It is so coiled that at eachpitch advance of the helix, a separate elliptical surface is formedwhich is displaced angularly from the preceding elliptical surface aboutthe surface of the drum, as best illustrated in Figure 5. Preferably,each elliptical surface is secured to a bar 53 at the minor axis of theellipse by ears 55 which are secured. to the resilient abrasive material54. Screws 58, rivets, or the like passing through the ears 55 firmlysecure the ears 55 to the bar 53.

It is obvious from the foregoing description that a novel sander rollunit has been described which will satisfactorily follow the contours ofa relatively flat surface for surface sanding. The helical method ofapplying the abrasive material also leaves the surface which is sandedperfectly smooth without the usual tell-tale sanding marks. It isfurther evident from the disclosure that since sanding rolls are usuallyoperated at relatively high peripheral speeds that the centrifugaleffect as the drum is rotated will tend to throw the surfaceof eachelliptical unit to its maximum diameter while the inner limitingdiameter of the sander roll is the point at which the abrasive issecured to the drum for each helical unit. A deformed sanding drum hastherefore been provided which has a substantially flexible and helicallymounted abrasive surface which is formed by substantially successiveelliptical surfaces displaced about the drum; and, the flexible sandingsurface so formed has as its maximum diameter substantially the majoraxis of the ellipse and as its minimum diameter substantially the minoraxis of the ellipse. With this construction it is apparent that theabrasive effect of the sanding drum as it is operated is self adjustingdepending upon the surface being sanded.

In the operation of the sanding machine, the material is being fedthrough from left to right, as illustrated in Figure l, and the uppersurface is first surface sanded after which the lower surface is surfacesanded. The sanding machine is capable of adjustment for variousthicknesses of material, and it is also possible to operate the machineso that only one surface is sanded. It is within the scope of theinvention that the sander roll units can be operated at any peripheralspeed depending upon the material being surface sanded. It is alsowithin the scope of the invention that the conveyors for feeding thematerial to the sanding machine can be operated at speeds which arerelatively low with respect to the peripheral speed of the sanding rollunit, but which are satisfactory for the successive operation of theapparatus. In the preferred embodiment of the invention, however, theperiph eral speed of the sanding drum and feed of the conveyors of thesanding machine are within the range of accepted practice.

Although there has been shown in this embodiment a combination of novelfeatures, all

cooperating functionally to provide an improved sanding machine, it isto be understood that the invention, as defined by the following claims,includes the various subcombinations of elements which may be utilizedwith improved results over the existing structures known in the art.

While the above construction illustrates a preferred embodiment ofthe-invention, the details of construction described are not essentialand may be varied without departure from the scope of the invention asdefined in the following claims.

What is claimed is:

1. In a sanding machine adapted for surface sanding, a sanding means inthe form of a drum comprising a flexibly mounted abrasive surface forsurface sanding, said abrasive surface comprising a plurality ofsubstantially elliptical sanding surfaces and helically formed by anarrow strip of abrasive material secured to the drum about itscircumference at substantially the minor axes of the ellipses and insubstantially equally displaced steps, and the cross-section through theabrasive strip for each pitch advance of the abrasive stripsubstantially in the form of an ellipse.

2. A sanding drum for surface sanding comprising a flexibly andsubstantially helically mounted abrasive surface,'said abrasive surfaceformed by substantially successive elliptical surfaces angularlydisplaced about. the drum with respect to each other, whereby a flexiblesanding surface is formed having as its maximum diameter substantiallythe major axis of the ellipse and as its minimum diameter substantiallythe minor axis of the ellipse.

3. In a sanding machine adapted for surface sanding, sanding meanscomprising a drum and a flexible sanding element carried thereby, saidsanding element comprising a continuous strip of abrasive surfaceapplied helically about said drum, the convolutions of said strip spacedfrom each other, the cross section of said strip in each convolutionsubstantially in the form of an ellipse, and said strip in eachconvolution secured to said drum substantially in the region of theminor axis of its elliptical form leaving the remainder of the strip ineach convolution unsupported, the successive convolutions of said striphaving their major axes angularly displaced about the drum with respectto each other, whereby the abrasive surface of the sanding element isflexibly conformative to the surface of the material being sanded.

4. A sanding drum for surface sanding comprising a flexibly andsubstantially helically mounted member having an abrasive surface, saidabrasive surface. formed by a plurality of successive substantiallyelliptical surfaces angularly displaced about the drum with respect toeach other, said member secured to the drum only in the region of theminor axes of the elliptical surfaces, whereby a flexible sandingsurface is formed having as its maximum diameter substantially the majoraxis of the ellipse and as its minimum diameter substantially the minoraxis of the ellipse.

FLOYD W. ADAMS.

